There has been a tactile sensation producing apparatus which includes a display, a contact detector that detects a contact state of user's manipulate operation to the display and a haptic vibration generating part which generates haptic vibration that gives a designated sensation to the user's body-part contacting the display (for example, see Patent Document 1).
The tactile sensation producing apparatus further includes a vibration waveform data generating means which generates a waveform data based on a detected result of the contact detector. The waveform data is used for generating the haptic vibration. The tactile sensation producing apparatus further includes an ultrasound modulating means which performs a modulating process on the waveform data by utilizing an ultrasound as a carrier wave and outputs an ultrasound signal generated by the modulating process to the haptic vibration generating means as a signal used for generating the haptic vibration.
The ultrasound modulating means performs either a frequency modulation or a phase modulation. The ultrasound modulating means further performs an amplitude modulation.
However, a ultrasound frequency used in the conventional tactile sensation producing apparatus may be any frequency as long as the frequency is higher than that of an audio frequency (about 20 kHz). No specific setting is made for the ultrasound frequency. Accordingly, the tactile sensation producing apparatus cannot provide a fine or crisp tactile sensation to the user.